However, one of the images shows an iPhone 4 in a bag, the assembled unit having seemingly been rejected for a fault in its camera lens, bearing the code number N90A.

This is significant, Gizmodo says, as this code number has been spotted before, with 9to5Mac last week receiving an anonymous tip that this is the code for a modified iPhone 4 (which uses the N90 code), perhaps with 8GB of flash memory, rather than the 16GB or 32GB usually offered.

An 8GB version would presumably be cheaper than the current iPhone 4, but the question that remains is which market it is intended for. We'd guess that it is likely to be aimed at the Brazilian market itself, though it is possible that it will become Apple's low-cost option for all markets.

All will become clear tomorrow, we expect. Macworld.co.uk will have a live text feed from Cupertino so join us from around 6pm BST for all the news.